Multiple Time Windows for Technician Routing

Answered

Baris Kafa

March 07, 2024 07:45

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Hello, 

I want to add multiple time windows for Techician Routing Scheduling Examples in Gurobi Example. 

How can i do that? Could you share some code blocks? 

Thank you. 

 

Related to

• Scheduling

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• Official comment

  

  Simranjit Kaur

  • Gurobi Staff

  November 13, 2026 01:28

  This post is more than two years old. Some information may not be up to date. For current information, please check the Gurobi Documentation or Knowledge Base. If you need more help, please create a new post in the community forum, or try Gurobot, our chatbot interface offering instant, expert-level support.
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  Riley Clement

  • Gurobi Staff

  March 08, 2024 10:08

  Hi Baris,

  Is the problem you're considering an extension of the one in this notebook:
  https://colab.research.google.com/github/Gurobi/modeling-examples/blob/master/technician_routing_scheduling/technician_routing_scheduling.ipynb
  but where each customer has a set of disjoint time windows that the technician can arrive in, instead of a single time window?

  - Riley

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• 

  Baris Kafa

  March 11, 2024 07:08 Edited

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  Hi Riley, 

  i see that notebook. My question is about a customer having multiple time windows.

  This is how we currently use it.
  tStart = {j.name : j.tStart for j in customers}
  tEnd = {j.name : j.tEnd for j in customers}

  The form I want to use is;
  tStart1 = {j.name : j.tStart1 for j in customers}
  tEnd1 = {j.name : j.tEnd1 for j in customers}

  tStart2 = {j.name : j.tStart2 for j in customers}
  tEnd2 = {j.name : j.tEnd2 for j in customers}

  tStart3 = {j.name : j.tStart3 for j in customers}
  tEnd3 = {j.name : j.tEnd3 for j in customers}

  
  How can I combine these 3 different time windows?

  Thank you. 

  -Baris

   

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• 

  Riley Clement

  • Gurobi Staff

  March 11, 2024 09:54

  Hi Baris,

  Currently the time windows are enforced with the following constraints,

  t_j >= a_j - xa_j
  t_j <= b_j + xb_j

  where t_j is the arrival time at location j, and time window at location j is [a_j, b_j].

  Suppose instead you want 3 time windows, [a_{j1}, b_{j1}], [a_{j2}, b_{j2}], [a_{j3}, b_{j3}].  You can introduce binary variables w_{j1}, w_{j2}, w_{j3} to indicate the choice of window.  You have to introduce constraints for each j to make sure a window is chosen:

  w_{j1} + w_{j2} + w_{j3} = 1

  and then the start time of the window is equal to

  a_{j1}w_{j1} + a_{j2}w_{j2} + a_{j3}w_{j3}

  and the end time of the window is equal to

  b_{j1}w_{j1} + b_{j2}w_{j2} + b_{j3}w_{j3}

  and you can use these expressions in place of a_j and b_j in the original time window constraints.

  - Riley

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